1. Field of the Invention
This invention relates to the field of sampling air from the lungs and specifically to the field of obtaining a sample of a person""s air, including alveolar air from the alveoli of the lungs of a person.
2. Description of the Prior Art
Air from the lungs of a person can be used for many different types of testing that would otherwise require the person to undergo an invasive procedure. For example, alveolar air can be analyzed for, but not limited to, the noninvasive diagnosis of a wide variety of conditions including the noninvasive diagnosis of stomach infections related to a high incidence of ulcers, enzymatic deficiencies, and metabolic conditions and/or abnormalities. Crucial to any such testing is the ability to get an accurate sample containing a sufficient volume of air representative of true alveolar air, necessary for specific testing.
A simple to use, inexpensive, and user-friendly apparatus is desired to collect and store human breath samples. In order to collect true alveolar air, an apparatus smaller in potential volume than the volume of a human breath is desired, in order to purge air from the apparatus and subject to be tested that is not true alveolar air. One such apparatus is disclosed in U.S. Pat. 5,432,094 to Delente (Jul. 11, 1995). Another such apparatus is disclosed in U.S. Pat. 5,327,901 to Delente (Jul. 12, 1994).
However, the two Delente disclosures are not flexible and depend on rigid storage means. Additionally, the two Delente disclosures begin with storage means that are originally filled with ambient air. Because the Delente disclosures are filled with ambient air, the ambient air must first be purged from the storage means. This allows for the possibility that the sample will ultimately contain a portion of ambient air, as opposed to containing entirely human breath.
Often it is necessary to transport the air sample in the sample container for long distances, frequently by airplanes to the location of a special gas analyzer. It is necessary to have a sample container that is cost efficient, light weight, dependable and capable of withstanding contraction and expansion common to high elevation and pressure changes without bursting and losing the sample. Additionally, it is desirable to have a sample container that is easy to operate, without risk of sample contamination due to dilution, diffusion, or through interaction of the sample and container materials.
An air sampling device for sampling air received from the exhalation of breath of a person is disclosed. The air sampling device is comprised of a breath intake structure used to exhale a breath into an expandable bag structure through an inlet. The breath intake structure can be constructed of commonly available materials, and a drinking straw may be the preferred breath intake structure. The expandable bag structure is preferably constructed of a supple, airtight, gas impermeable, and inert material.
An adhesive patch is adhered to an interior surface of the inlet, and the adhesive patch is selectively covered by a removable adhesive patch cover selectively adhered the first side of the adhesive patch. The breath intake structure is selectively communicatively coupled with expandable bag structure through the inlet, between a second interior surface of the inlet and the removable adhesive patch cover.
The adhesive patch is coextensive with the inlet at one end, and another end extends into the interior of the expandable bag structure. The removable adhesive patch cover is at one end coextensive with the adhesive patch first end, and the removable adhesive patch cover extends into the expandable bag structure interior at least to the adhesive patch second end, and the other end of the removable adhesive patch cover extends out of the inlet.
An adhesive inlet seal patch is provided to supply additional seal to the expandable bag structure, beyond the seal provided by the adhesive patch. The adhesive inlet seal patch can be labeled with a sample identifier, such as possibly a barcode or machine-readable system. The sample identifier provides a convenient method for sequentially labeling air samples, or should the samples include a preloaded dessicant or a chemical indicator, or should samples from different patients be shipped together.
In another embodiment of the present invention, the air sampling device can include an outer shell encapsulating the expandable bag structure. The outer shell can capture the air sample should the expandable bag structure rupture. The outer shell has an outer shell inlet to the expandable bag structure interior providing a conduit for the breath intake structure. In this embodiment, the breath intake structure is selectively communicatively coupled with the expandable bag structure interior between the one interior surface of the expandable bag structure inlet and the removable adhesive patch cover. In this embodiment, the adhesive inlet seal patch is applied to the exterior of the outer shell. Again, the adhesive inlet seal patch can include the sample identifier. The outer shell is sized to contain a volume greater than a volume of the inner expandable bag structure, so that if the air sample is depressurized and ruptures the inner expandable bag structure, the outer shell will still contain the air sample.
A method for using the air sampling device is also disclosed and is substantially as follows. The breath intake structure is inserted into the expandable bag structure inlet between a second interior surface of the inlet and the removable adhesive patch cover. A patient places the breath intake structure into the mouth against his or her lips and exhales into it in a normal manner. During an initial phase of a patient""s exhalation into the breath intake structure, the expired air flows into the initially empty expandable bag structure, filling the expandable bag structure. During the remaining phase of the patient""s exhalation through the intake structure, the breath from the initial phase of the patient""s exhalation is expelled through the inlet, and is replaced by alveolar air that remains in the expandable bag structure.
To seal the expandable bag structure, the breath intake structure and removable adhesive patch cover are grasped and withdrawn from the expandable bag structure interior and the exterior surfaces of the inlet are pressed together, adhering the interior surfaces against the adhesive patch.
Next, to further seal the expandable bag structure if desired, the adhesive inlet seal patch is separated from the adhesive inlet seal patch cover, and the adhesive inlet seal patch is applied to the expandable bag structure, further sealing the inlet. The sample identifier can be either written or pre-labeled on the adhesive inlet seal patch or outer shell.
If an outer shell is employed, the same sampling methodology is used, with the exception that following the step of pressing together the exterior surfaces of the inlet with the adhesive patch, the adhesive inlet seal patch is separated from the adhesive inlet seal patch cover, and the adhesive inlet seal patch is applied to the outer shell, covering the outer shell inlet.
If the expandable bag structure bursts, the outer shell will still contain the air sample. Accordingly, when a person exhales into the breath intake structure, a first predetermined volume of breath enters the expandable bag structure until the expandable bag structure is expanded to its predetermined size Next, the remainder of the breath, which includes alveolar air from the person""s lungs, enters and expands the expandable bag structure and forces the waste air from the expandable bag structure. This results in the expandable bag being filled with a sample of alveolar air.